Need to weed out a liar? Try tricking them with a choice. Because liars have to think so much to keep track of their lies, they'll often be unable to come up with an alternate to the options you provide.

Dr. John R. Schafer, writing for Psychology Today, is back with another great tip to help you uncover a lie. He suggests that offering a liar a choice is an easy way to tell when they're full of crap:

Liars, when faced with two choices, tend to pick one of the choices presented rather than seeking a third alternative. This tendency is due to cognitive overload. Truthful people do not experience cognitive overload; they simply convey facts. Liars, on the other hand, are operating at near-full or full cognitive capacity depending on the complexity of the lies.

For example, you can start off with a yes or no question like, "did you take the last cookie from the cookie jar?" They'll probably lie and answer no, so ask them "did you think I wouldn't find out that you did it?" If they answer yes or no this time, they're caught in the lie. If they're telling the truth, however, they'll have the cognitive capacity to easily tell you that you're out of your mind.